Validation and cost-effectiveness of a home-based screening system for amblyopia.

PURPOSE: To investigate the cost-effectiveness of a novel home-based screening system for amblyopia and amblyogenic risk factors. DESIGN: Evaluation of diagnostic test or technology. PARTICIPANTS: Two thousand four hundred forty-two preschoolers 3 to 6 years of age from 10 kindergartens randomly selected from Guangzhou participated in the study in 2009. METHODS: Preschoolers were assessed for amblyopia and amblyogenic risk factors by their parents using the home-based screening system and were re-evaluated by professionals who conducted a comprehensive eye examination. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive predictive value, negative predictive value, and the cost-benefit of the home-based screening system were calculated by comparing the results from the home-assessed model and those from the professional evaluation. RESULTS: Three thousand three hundred children were invited to participate in the study, and 2308 (1216 boys and 1092 girls) completed all of the procedures. Twenty-four amblyopes were found by professional examinations. Fifteen of these amblyopes had not been diagnosed previously, and 12 of them were detected by the home-assessment model. The sensitivity, specificity, positive predictive value, and negative predictive value were 80.0%, 94.1%, 8.2%, and 99.9%, respectively. Professional examinations cost an average of US $1131.00 per case of amblyopia detected, whereas the cost was only US $266.00 per case for the home-based method. For amblyogenic factors, 50, 87, and 96 children were classified into grade I, II, or III according to the professional examinations. The corresponding numbers in the home-based system were 23, 29, and 15, respectively. Accordingly, the true positive rates were 46.0%, 33.3%, and 15.6% for each grade. CONCLUSIONS: The home-based amblyopia screening system was found to be a simple, effective, and cost-beneficial method for amblyopia screening and amblyogenic risk factors. The approach offers a practical option for developing areas with large populations. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Provision and cost of children's and young people's eye services in the UK: findings from a single primary care trust.

AIMS/BACKGROUND: Population-based information is useful for future strategic planning of healthcare resources. We wished to describe and cost the provision of eye services, beyond those of basic primary and emergency care, for the paediatric population of a single primary care trust. METHODS: Data from healthcare purchaser and provider records were collected for the year 2004/5 on provision and costing of hospital eye services, provision of spectacle vouchers, orthoptic screening, social services and visual-impairment team services to children in the Huntingdonshire Primary Care Trust population. RESULTS: In the year of study, in a population of 33,564 aged under 18 years, 1870 (5.6%) children underwent screening by an orthoptist. 1970 (5.9%) children required outpatient appointments, 445 (1.3%) were prescribed spectacles, and 87 (0.3%) children needed surgical procedures. A small proportion (69, 0.2%) of children were visually impaired. The total cost of providing comprehensive eye services to children within Hunts PCT was pound 366,727. CONCLUSION: Although the prevalence of significant visual impairment is low in childhood, overall, eye conditions are common in children and may have lifelong implications. The resources required to provide a comprehensive paediatric eye service, to screen for and manage common eye conditions, and support those with serious eye conditions or visual impairment, are significant. This study aids quantified prediction of future service usage, and facilitates decision-making on resource allocation and workforce organisation for children's eye care in the UK.

Cost-utility analysis of orthoptic screening in kindergarten: a Markov model based on data from Germany.

OBJECTIVE: To estimate the long-term cost-effectiveness of a hypothetical screening program for untreated amblyopia in 3-year-old children conducted by orthoptists in all German kindergartens in the year 2000. METHODS: A cost-utility analysis was performed for which a decision tree was combined with a Markov model. Incremental costs and effects during the children's remaining lifetime were estimated. The model took into account the probability of treatment without screening, age-specific treatment success rates, costs of screening and treatment, as well as effects of unilateral and bilateral visual impairment caused by amblyopia and other eye diseases coming along later in life on quality of life (utility). Model parameter values were obtained from a field study of orthoptic screening in kindergarten, from the literature, and from expert interviews. Costs were estimated from a third-party payer perspective. Uncertainty was assessed by univariate and probabilistic sensitivity analysis (Monte Carlo simulation). RESULTS: The incremental cost-effectiveness ratio (ICER) of orthoptic screening was 7397 Euro (euro) per quality-adjusted life year (QALY) when costs and effects were discounted at 5%. In univariate sensitivity analysis, the ICER was sensitive to the uncertainty regarding the utility of unilateral visual impairment and to the discount rate for effects; besides uncertainty regarding the prevalence of untreated amblyopia, the odds ratio of success of treatment when started late, and the probability of treatment without screening had a noticeable but much smaller effect. Monte Carlo simulation yielded a 90% uncertainty interval for the ICER of 3452 euro/QALY to 72 637 euro/QALY; the probability of an ICER <25 000 euro/QALY was 84%. CONCLUSIONS: The ICER of orthoptic screening seems to fall within a range that warrants careful consideration by decision-makers. Much of the uncertainty in results comes from the uncertainty regarding the effect of amblyopia on quality of life. To reduce this uncertainty, the impact of amblyopia on utility should be investigated.

Cost-effectiveness of orthoptic screening in kindergarten: a decision-analytic model.

PURPOSE: The purpose of this study was to analyze the cost-effectiveness of orthoptic screening for amblyopia in kindergarten. METHODS: A decision-analytic model was used. In this model all kindergarten children in Germany aged 3 years were examined by an orthoptist. Children with positive screening results were referred to an ophthalmologist for diagnosis. The number of newly diagnosed cases of amblyopia, amblyogenic non-obvious strabismus and amblyogenic refractive errors was used as the measure of effectiveness. Direct costs were measured form a third-party payer perspective. Data for model parameters were obtained from the literature and from own measurements in kindergartens. A base analysis was performed using median parameter values. The influence of uncertain parameters was tested in sensitivity analyses. RESULTS: According to the base analysis, the cost of one orthoptic screening test was 7.87 euro. One ophthalmologic examination cost 36.40 euro. The total cost of the screening program in all kindergartens was 3.1 million euro. A total of 4,261 new cases would be detected. The cost-effectiveness ratio was 727 euro per case detected. Sensitivity analysis showed considerable influence of the prevalence rate of target conditions and of the specificity of the orthopic examination on the cost-effectiveness ratio. CONCLUSIONS: This analysis provides information which is useful for discussion about the implementation of orthoptic screening and for planning a field study.

[Cost effectiveness of mass orthoptic screening in kindergarten for early detection of developmental vision disorders]. / Kosteneffektivität der orthoptischen Reihenuntersuchung im Kindergarten zur Früherkennung visueller Entwicklungsstörungen.

PURPOSE: Orthoptic screening in the kindergarten is one option to improve early detection of amblyopia in children aged 3 years. The purpose of this study was to analyse the cost-effectiveness of such a screening programme in Germany. METHODS: Based on data from the literature and own experience gained from orthoptic screening in kindergarten a decision-analytic model was developed. According to the model, all children in kindergarten, aged 3 years, who had not been treated for amblyopia before, were subjected to an orthoptic examination. Non-cooperative children were reexamined in kindergarten after one year. Children with positive test results were examined by an ophthalmologist for diagnosis. Effects were measured by the number of newly diagnosed cases of amblyopia, non-obvious strabismus and amblyogenic refractive errors. Direct costs were estimated from a third-party payer perspective. The influence of uncertain model parameters was tested by sensitivity analysis. RESULTS: In the base analysis the cost per orthoptic screening test was DM 15.39. Examination by an ophthalmologist cost DM 71.20. The total cost of the screening programme in all German kindergartens was DM 6.1 million. With a 1.5% age-specific prevalence of undiagnosed cases, a sensitivity of 95% and a specificity of 98%, a total of 4,261 new cases would be detected. The cost-effectiveness ratio was DM 1,421 per case detected. Sensitivity analysis showed considerable influence of prevalence and specificity on the cost-effectiveness ratio. It was more cost-effective to re-screen non-cooperative children in kindergarten than to have them examined by an ophthalmologist straight-away. CONCLUSIONS: The decision-analytic model showed stable results which may serve as a basis for discussion on the implementation of orthoptic screening and for planning a field study.

Methodology for a randomised controlled trial of preschool vision screening. A new approach with the 'ALSPAC' project.

We present the methodology of a population-based Randomised Controlled Trial, comparing an intensive programme of primary preschool vision screening by orthoptists with the usual non-specialist screening. The aims of the trial are to compare the effectiveness and costs of intensive orthoptic screening with non-specialist measures. The orthoptic screening programme will be evaluated both as a composite package and in terms of the screening value of the individual tests at specific ages. This trial is nested within a large population-based longitudinal study. Additional demographic and developmental data on the children in the trial are therefore available. The results of the trial will be used to help clarify which methods of preschool ophthalmic population screening are best in terms of disease detection and cost efficiency.